I've had a very similar build as the OP, starting with HD4000, then add the Gigabyte GTX-670 and re-installed all over again:
1. The on-board HD4000 worked normally and I could change its resolution to match the highest solution of my monitor used for installation.
2. Both wired-ethernet ports worked normally.
Now, these are my problems and any help will be greatly appreciated:
a/. I have to use the Marvel ports (actually I've had a BD burner, 2 SSDs for OSes, 3 HDDs: 1TB exFAT, 2TB and 3TB NTFS) so auto-sleep not working in both OS X and Windows 7! Manual sleep and wake normally in both OSes.
b/. Tried using HDMI out: perfect in Windows, perfect video in OS X but without audio. I hesitated to tweak it myself, at least for now.
c/. OS X DVD player not working "a valid drive could not be found. Error ...". This seems to be a common problem?
d/. I am planning to get the Apple wireless keyboard and trackpad, then which is the most reliable bluetooth dongle and can work OOB? Is the Rocketfish Micro Bluetooth USB Adapter (RF-MRBTAD) the correct choice? Right now, I've used the wireless Logitech K400 keyboard with trackpad and it worked OOB during BIOS and in both OSes.
TIA.